Latch assembly



Feb. 4, 1969 B. E. ETTl-:R

LATCH ASSEMBLY Filed Jan. 2a, 196e United States Patent (1F 4 Claims ABSTRACT F THE DISCLOSURE A latch assembly is comprised of a movable latch unit and three independently operating latch actuating units. Two of the latch actuating units are each comprised of a knob and a latch actuating means interconnected by a shaft. The third unit is a key mechanism connected by a shaft to a latch actuating means.

This invention relates to a latch assembly and in particular to an improved latch assembly for opening and closing doors or the like.

The conventional door latch assembly includes actuating units on opposite sides of the door for operating the latch unit. A single solid shaft may be used to interconnect the actuating units on opposite sides of the door and when the knob on one side of the door is turned, the knob on the opposite side of the door will also Ibe turned. Thus, the door knobs or the like will turn together as a unit.

Accordingly, it is one of the objects of this invention to provide a latch assembly which will allow actuating units on opposite sides of a door to operate independently of each other and additionally provide for the independent operation of a key mechanism for operating the latch unit if desired.

Another object of this invention is to provide a latch assembly employing three coaxial shafts each operable independently of the other and being connected to al door knob actuating unit or key mechanism actuating unit.

It is a still further object of this invention to provide a latch assembly having a trio of cam elements positioned in side by side relationship for operation of the latch unit.

A still further related object of this invention is to provide a latch assembly having coaxial telescoping shafts which are square in cross-section for independent engagement with individual cam elements.

Another related object of this invention is to provide a latch assembly having locking means within associated actuating [means wherein the actuating means is on the opposite side of the door from the actuating unit adapted to -be locked by said locking means.

A further object of this invention is to provide a latch assembly which is simple in design, economical to manufacture fand relined in appearance.

These and other objects will be apparent to those skilled in the art.

This invention consists in `the construction, arrangements, and combination of the various par-ts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings -in which:

FIG. 1 is a fragmentary partial cross-sectional view of the latch assembly mounted in a door;

FIG. 2 is an exploded perspective view partially in cross-section of the latch assembly only;

FIG. 3 is a partially cross-sectioned elevation view of the trio of coaxial shafts and their respective cam elements; and

FIG. 4 is `an end elevational view taken along line 4 4 in FIG. 3.

3,425,247 Patented Feb. 4, 1969 The latch assembly of this invention is referred to generally in FIG. 2 by the reference numeral 10 and is shown in FIG. 1 mounted in a door 12. It is seen that a latch unit 14 is disposed between a pair of door knob actuating units 16 and 18. The door knob unit 16 also includes 'a key mechanism actuating unit 20.

The latch unit 14 includes a housing 22 for a latch bolt 24 which is normally spring biased to its extended position as seen in FIGS. 1 and 2. The inner end of the latch bolt includes a pair of spaced apart lingers 24 and 26 having transversely extending end portions .28 and 30 respectively. A pair of aligned openings 32 are formed in the latch unit housing 22 lbetween the finger portions 24 and 26 and adjacent the end portions 28 and 30. A second pair of aligned holes 34 extend through the side walls of the latch unit housing 22 adjacent the rst laligned holes 3,2. The key mechanism 20 in the outside door actuating knob 16 includes an inner stub shaft 36 adapted to rotate within 4the knob 16 and has a square in crosssection longitudinal axial hole 38. The inner end of the door knob 16 is provided with la coaxial square in crosssection hole 40. The square hole 40 is adapted to receive a square shaft 42 while the square hole 38 receives a shaft 44 having a square in cross-section end portion 46. The shaft 44 is circular in cross-section for telescoping rotational engagement inside the shaft 42. At the opposite end of the shaft 44 from the knob 16, a square in cross-section portion 48 is provided which merges into a circular in cross-section portion 50 having an annular groove 52 formed therein adjacent its outer end.

A first semi circular plate cam element 54 mounted on a hub 56 having a square in cross-sectional hole 58 is provided for engagement with the square in cross-section outer `shaft 42. A second semi circular plate cam element 58 is mounted on a hub `60 having a square in cross-sectional hole 62 for mating engagement with the square in cross-section portion 48 on the shaft 44. As seen in FIG. 3, the hub 60 is rotatably received Within the hub 56.

A third shaft 64 is provided for engagement in a hole 66 formed in the inner end of the kno'b actuating unit 18. This shaft 64 is square in cross-section 4and has a circular longitudinal center hole 68 for receiving the circular in cross-section portion 50 of thc shaft 44. A pin 70 is provided for engagement in the arcuate recess 52 to lock the shafts 42 and 44 to the shaft 64. A third semi circular plate cam element 72 mounted on a hub 74 is provided and has a square in cross-section hole 76 for receiving the square shaft 64. As seen in FIG. 1, the cam elements 54, 58 and 72 lare positioned between the side walls of the latch unit housing 22 with 4the hubs 56, 60 and 74 rotatably mounted in the `axial openings 32 formed in the housing 22. Thus, upon rotation of the cam elements the back edges thereof will engage one or the other of the transversely extending portions 28 and 30 on the fingers 24 and 26 respectively.

An inside lock actuator element 80 is mounted on the longitudinal center axis of the door knob 18 and is movable between locked and unlocked positions where it is held by a iball and spring detent 82 and 84 respectively. The ball 82 is adapted to engage a depression 86 in the actuator element 80 when it is extended and engage a depression 88 when it is moved inwardly to the locking position as shown in FIG. 1. An elongated pin 90 is secured to the peripheral surface of the actuator element 80 and extends through an .arcuate opening 92 formed in the door knob 18 whereby the `actuator element with the pin 90 may be rotated relative to the door knob 18 approximately 30 degrees about the longitudinal center axis of the dor knob 18. The inner end of the pin 90 extends through the aligned holes 34 in the latch unit housing 22 and is adapted to be received in a hole 94 in a stop element 96 secured to the outer peripheral edge of the shaft 42. Thus when the actuator element 80 is depressed the pin 90 locks the shaft 42 against rotational movement since the pin extends through the latch unit housing Z2 and cannot move about the longitudinal center axis of the shafts.

Thus in operation, it is seen that by the use of square shafts the la-tch unit 14 may be operated by either of door knob actuating units on opposite sides of a door or by a key 100 in a lock mechanism 20 associated with the door knob actuating unit 16. By depressing the actuator element 80, for instance located on the inside of the door the outside `door knob 16 is locked lagainst rotational movement since the pin 90 is received in the hole 94 in the lock element 96 mounted on the shaft 42 connected to the door knob 16. The entire assembly may be assembled or disassembled by removal of the pin 70 mounted in the shaft 64 which receives the inner end 50 of the shaft 44. The cam elements 54, 58 and 72 are all conveniently closely spaced -together between the side walls of the latch unit 14 housing 22 for engaging the inner end portions 28 and 30 of the latch bolt 24.

Accordingly, complete independence of operation is provided in actuating latch bolt 24 by either the key 100 or the outer or inner door knobs 16 and 18 respectively. The operation described is accomplished by a minimum of component part using a minimum of material and requiring a minimum amount of space.

Some changes may be made in the construction and arrangement of my latch assembly without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim:

1. A latch assembly, comprising,

a latch unit including a movable latch member,

a first latch actuating unit having a first knob member and a first cam member interconnected by a first shaft member,

a second latch actuating unit having a second knob member and a second cam member interconnected by a second shaft member,

4 a third latch actuating unit having a key mechanism and a third cam member interconnected by a third shaft member,

each of said cam members being in engagement with said latch member for operation thereof,

each of said latch actuating units being completely independently movable to operate said, latch member with respect to the other units.

2. The combination of claim 1 wherein said third shaft extends rotatably through said first shaft and is rotatably received within said second shaft.

3. The combination of claim 1 wherein a lock actuator extends from said first knob to a stop element on said second knob, said lock actuator being movable from an unlocked position free from engagement with said stop means to a locked position in engagement with said stop means to hold said second knob against rotational movement.

4. The structure of claim 1 wherein the three cam members are disposed in close side by side relationship, said third shaft member extending rotatably through said first and second cam members, said third shaft member having a square cross-sectional portion thereof extending thfough a square lhold in said third cam member in mating engagement therewith.

References Cited UNITED STATES PATENTS 1,611,052 12/1926 Malicki 292-169 1,724,630 8/ 1929 Wilson 292-169 2,544,959 3/ 1951 Hillgren 292-169 2,702,466 2/ 1955 McConnell 70-216 X 3,233,439 2/1966 Papas 292-169 X MARVIN A. CHAMPION, Plrmay Examiner.

EDWARD J. MCCARTHY, Assistant Examiner.

U.S. C1. X.R. 292-169 

